The present invention relates generally to devices for injecting fluids into a fluid line and for sampling fluids flowing in a fluid line and more particularly to a fluid injection and sampling device combined with an in-line blender.
In many areas of technology it is frequently desirable to mix a fluid with one or more other substances while the substances are passing through a conduit en route to a delivery point. It has been necessary to mix gasses, liquids, and even some solids, of a powdered or particulate nature. In the past numerous devices have been employed to solve this problem, and these devices have been generally classified as in-line blenders and mixers, static or motionless blenders and mixers, or interfacial surface generators. Although such devices have taken on numerous forms, it is known in the art that a particularly effective means of mixing such substances includes a plurality of spiral flow paths which are periodically subdivided and reversed in direction of twist.
For example, U.S. Pat. No. 3,286,992 to Armeniades et al discloses a mixing device having a hollow cylindrical tube and a plurality of curved sheet-like elements extending in series longitudinally within the tube throughout the length thereof. The sheet-like elements have periodic reversals of curvature and are affixed to the walls of the tube.
U.S. Pat. No. 3,794,300 to Harder discloses an in-line blender having a shaft extending longitudinally through a conduit and having a plurality of sheet-like mixer elements spirally twisted about the shaft and affixed to it. Although such devices have generally performed in an acceptable manner, they have exhibited certain shortcomings. Since each mixing stage in these devices has been made of continuous sheet material, the amount of rotation imparted to the fluid per mixing stage has been fixed for each stage. Furthermore, the mixing stages in the prior devices have not been easily adjusted to change flow patterns and accomodate different flow conditions. Thus, different mixing devices have been required to satisfy different flow conditions. Additionally, although these devices have generally been effective for mixing under laminar flow conditions, they have not been as effective under turbulent flow conditions. Finally, such devices have usually been of a rather permanent nature and have not been easily disassembled for cleaning. It is also frequently desirable to inject fluids into a fluid line, or sample fluids flowing in the line. Thus, a need has developed for a fluid injection and sampling device which may be easily combined with an in-line blender to cooperate with the blending process.